﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Collections;

namespace TestForm
{
    public static class SqlHelper
    {
        
            /// <summary>
            /// 数据库连接字符串
            /// </summary>
            public static readonly string connectionString = @"Data Source=.;Initial Catalog=TemperatureChartTest;Persist Security Info=True;User ID=sa;Password=tudousi";
            // Hashtable to store cached parameters
            private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

            #region//ExecteNonQuery方法

            /// <summary>
            ///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。
            /// 使用参数数组形式提供参数列表 
            /// </summary>
            /// <param name="connectionString">一个有效的数据库连接字符串</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
            public static int ExecteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    //通过PrePareCommand方法将参数逐个加入到SqlCommand的参数集合中
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    int val = cmd.ExecuteNonQuery();
                    //清空SqlCommand中的参数列表
                    cmd.Parameters.Clear();
                    return val;
                }
            }

            /// <summary>
            ///执行一个不需要返回值的SqlCommand命令，通过指定专用的连接字符串。
            /// 使用参数数组形式提供参数列表 
            /// </summary>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
            public static int ExecteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecteNonQuery(connectionString, cmdType, cmdText, commandParameters);
            }

            /// <summary>
            ///存储过程专用
            /// </summary>
            /// <param name="cmdText">存储过程的名字</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
            public static int ExecteNonQueryProducts(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecteNonQuery(CommandType.StoredProcedure, cmdText, commandParameters);
            }

            /// <summary>
            ///Sql语句专用
            /// </summary>
            /// <param name="cmdText">T_Sql语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个数值表示此SqlCommand命令执行后影响的行数</returns>
            public static int ExecteNonQueryText(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecteNonQuery(CommandType.Text, cmdText, commandParameters);
            }

            #endregion
            #region//GetTable方法

            /// <summary>
            /// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接
            /// 使用参数数组提供参数
            /// </summary>
            /// <param name="connecttionString">一个现有的数据库连接</param>
            /// <param name="cmdTye">SqlCommand命令类型</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
            public static DataTableCollection GetTable(string connecttionString, CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                DataSet ds = new DataSet();
                using (SqlConnection conn = new SqlConnection(connecttionString))
                {
                    PrepareCommand(cmd, conn, null, cmdTye, cmdText, commandParameters);
                    SqlDataAdapter adapter = new SqlDataAdapter();
                    adapter.SelectCommand = cmd;
                    adapter.Fill(ds);
                }
                DataTableCollection table = ds.Tables;
                return table;
            }

            /// <summary>
            /// 执行一条返回结果集的SqlCommand，通过一个已经存在的数据库连接
            /// 使用参数数组提供参数
            /// </summary>
            /// <param name="cmdTye">SqlCommand命令类型</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
            public static DataTableCollection GetTable(CommandType cmdTye, string cmdText, SqlParameter[] commandParameters)
            {
                return GetTable(cmdTye, cmdText, commandParameters);
            }


            /// <summary>
            /// 存储过程专用
            /// </summary>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
            public static DataTableCollection GetTableProducts(string cmdText, SqlParameter[] commandParameters)
            {
                return GetTable(CommandType.StoredProcedure, cmdText, commandParameters);
            }

            /// <summary>
            /// Sql语句专用
            /// </summary>
            /// <param name="cmdText"> T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个表集合(DataTableCollection)表示查询得到的数据集</returns>
            public static DataTableCollection GetTableText(string cmdText, SqlParameter[] commandParameters)
            {
                return GetTable(CommandType.Text, cmdText, commandParameters);
            }
            #endregion


            /// <summary>
            /// 为执行命令准备参数
            /// </summary>
            /// <param name="cmd">SqlCommand 命令</param>
            /// <param name="conn">已经存在的数据库连接</param>
            /// <param name="trans">数据库事物处理</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">Command text，T-SQL语句 例如 Select * from Products</param>
            /// <param name="cmdParms">返回带参数的命令</param>
            private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
            {
                //判断数据库连接状态
                if (conn.State != ConnectionState.Open)
                    conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = cmdText;
                //判断是否需要事物处理
                if (trans != null)
                    cmd.Transaction = trans;
                cmd.CommandType = cmdType;
                if (cmdParms != null)
                {
                    foreach (SqlParameter parm in cmdParms)
                        cmd.Parameters.Add(parm);
                }
            }

            /// <summary>
            /// Execute a SqlCommand that returns a resultset against the database specified in the connection string 
            /// using the provided parameters.
            /// </summary>
            /// <param name="connectionString">一个有效的数据库连接字符串</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>A SqlDataReader containing the results</returns>
            public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                SqlConnection conn = new SqlConnection(connectionString);
                // we use a try/catch here because if the method throws an exception we want to 
                // close the connection throw code, because no datareader will exist, hence the 
                // commandBehaviour.CloseConnection will not work
                try
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    cmd.Parameters.Clear();
                    return rdr;
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
            #region//ExecuteDataSet方法

            /// <summary>
            /// return a dataset
            /// </summary>
            /// <param name="connectionString">一个有效的数据库连接字符串</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>return a dataset</returns>
            public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlConnection conn = new SqlConnection(connectionString);
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    SqlDataAdapter da = new SqlDataAdapter();
                    DataSet ds = new DataSet();
                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    return ds;
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }


            /// <summary>
            /// 返回一个DataSet
            /// </summary>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>return a dataset</returns>
            public static DataSet ExecuteDataSet(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteDataSet(connectionString, cmdType, cmdText, commandParameters);
            }

            /// <summary>
            /// 返回一个DataSet
            /// </summary>
            /// <param name="cmdText">存储过程的名字</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>return a dataset</returns>
            public static DataSet ExecuteDataSetProducts(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteDataSet(connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
            }

            /// <summary>
            /// 返回一个DataSet
            /// </summary>

            /// <param name="cmdText">T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>return a dataset</returns>
            public static DataSet ExecuteDataSetText(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteDataSet(connectionString, CommandType.Text, cmdText, commandParameters);
            }


            public static DataView ExecuteDataSet(string connectionString, string sortExpression, string direction, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlConnection conn = new SqlConnection(connectionString);
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    SqlDataAdapter da = new SqlDataAdapter();
                    DataSet ds = new DataSet();
                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    DataView dv = ds.Tables[0].DefaultView;
                    dv.Sort = sortExpression + " " + direction;
                    return dv;
                }
                catch
                {
                    conn.Close();
                    throw;
                }
            }
            #endregion


            #region // ExecuteScalar方法


            /// <summary>
            /// 返回第一行的第一列
            /// </summary>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个对象</returns>
            public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteScalar(SqlHelper.connectionString, cmdType, cmdText, commandParameters);
            }

            /// <summary>
            /// 返回第一行的第一列存储过程专用
            /// </summary>
            /// <param name="cmdText">存储过程的名字</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个对象</returns>
            public static object ExecuteScalarProducts(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteScalar(SqlHelper.connectionString, CommandType.StoredProcedure, cmdText, commandParameters);
            }

            /// <summary>
            /// 返回第一行的第一列Sql语句专用
            /// </summary>
            /// <param name="cmdText">者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>返回一个对象</returns>
            public static object ExecuteScalarText(string cmdText, params SqlParameter[] commandParameters)
            {
                return ExecuteScalar(SqlHelper.connectionString, CommandType.Text, cmdText, commandParameters);
            }

            /// <summary>
            /// Execute a SqlCommand that returns the first column of the first record against the database specified in the connection string 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">一个有效的数据库连接字符串</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
            public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();

                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                    object val = cmd.ExecuteScalar();
                    cmd.Parameters.Clear();
                    return val;
                }
            }

            /// <summary>
            /// Execute a SqlCommand that returns the first column of the first record against an existing database connection 
            /// using the provided parameters.
            /// </summary>
            /// <remarks>
            /// e.g.:  
            ///  Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
            /// </remarks>
            /// <param name="connectionString">一个有效的数据库连接字符串</param>
            /// <param name="cmdType">SqlCommand命令类型 (存储过程， T-SQL语句， 等等。)</param>
            /// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
            /// <param name="commandParameters">以数组形式提供SqlCommand命令中用到的参数列表</param>
            /// <returns>An object that should be converted to the expected type using Convert.To{Type}</returns>
            public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
            {
                SqlCommand cmd = new SqlCommand();
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }

            #endregion


            /// <summary>
            /// add parameter array to the cache
            /// </summary>
            /// <param name="cacheKey">Key to the parameter cache</param>
            /// <param name="cmdParms">an array of SqlParamters to be cached</param>
            public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
            {
                parmCache[cacheKey] = commandParameters;
            }

            /// <summary>
            /// Retrieve cached parameters
            /// </summary>
            /// <param name="cacheKey">key used to lookup parameters</param>
            /// <returns>Cached SqlParamters array</returns>
            public static SqlParameter[] GetCachedParameters(string cacheKey)
            {
                SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];
                if (cachedParms == null)
                    return null;
                SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];
                for (int i = 0, j = cachedParms.Length; i < j; i++)
                    clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();
                return clonedParms;
            }


            /// <summary>
            /// 检查是否存在
            /// </summary>
            /// <param name="strSql">Sql语句</param>
            /// <returns>bool结果</returns>
            public static bool Exists(string strSql)
            {
                int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, null));
                if (cmdresult == 0)
                {
                    return false;
                }
                else
                {
                    return true;
                }
            }

            /// <summary>
            /// 检查是否存在
            /// </summary>
            /// <param name="strSql">Sql语句</param>
            /// <param name="cmdParms">参数</param>
            /// <returns>bool结果</returns>
            public static bool Exists(string strSql, params SqlParameter[] cmdParms)
            {
                int cmdresult = Convert.ToInt32(ExecuteScalar(connectionString, CommandType.Text, strSql, cmdParms));
                if (cmdresult == 0)
                {
                    return false;
                }
                else
                {
                    return true;
                }
            }
        }
    }

